Residents of Poverty Bay had felt many of the aftershocks of the Hawke’s Bay quakes of February 1931 and, as they decreased in frequency, life began to return to normal.

Forty kilometres inland from Gisborne, at the small settlement of Tiniroto, the 40-odd residents were well-advanced with building and chimney restoration work by May of 1931. However, they had noticed a peculiar aspect of the earthquakes since February.

Three months after the devastating Hawke’s Bay earthquake and firestorm, communities along much of the North Island’s eastern coast were still in recovery and assessment mode.

Clearance of rubble had largely been completed in Manawatu, Wairarapa and the Gisborne – East Coast areas. Insurance assessors were still busy compiling their reports, and many chimneys had been repaired or replaced in preparation for the winter months.

Another new menu at The Roundabout pub in Tawa sees the return of the noble burger. There’s chicken and a beef/cheese ensemble with the option of an egg, and the kiwi requirement of a slab of beetroot is catered for.

Geonet, the USGS (NEIC) and GNS Science reported 61 earthquakes in the New Zealand area between the Kermadec Islands in the north, and the Auckland Islands to the south during April 2006. The magnitude distributions were as follows:
M6 to 6.9 (1), M5 to 5.9 (21), M4 to 4.9 (30) M3 to 3.9 (7).
An additional 2 events in the magnitude 2 range were deemed worthy of mention.

Aftershocks following Thursday’s magnitude 7.9 earthquake centred 160 km north-east of Tonga’s capital Nuku’alofa have been erratic over the past four days.

Normally, a large earthquake is followed by a series of earthquakes which tend to decrease in frequency and strength over time, with occasional members of the sequence being of higher magnitude. This illustrates the crust surrounding the area of the rupture reacting to the change in stress caused by the large earthquake.

Tonga’s aftershock series has not followed this trend, but I hasten to add that not all earthquake sequences follow this trend of decreasing activity. Even in New Zealand, we see earthquake and aftershock sequences that don’t “follow the rules.”

It is reported that several hundred Gisborne and East Coast residents took the decision to evacuate their houses and head for higher ground following news of the strong earthquake near Tonga this morning.

While Civil Defence authorities dithered, people reacted to radio and extensive reporting of the earthquake and tsunami risk on satellite television channels.